1. Field of the Invention
This application relates generally to fence layout systems, particularly those which are used to confine livestock and other valuable animals.
2. Description of the Prior Art
Fences are the most commonly employed means for confining livestock such as commmon farm animals, steers, and even thoroughbred race horses. Fences may vary greatly in both structure and materials of composition. Common fence structures include wire fences, such as barbed wire or chain link, and wood fences, such as picket fences and split rail fences. Common fence materials include metal, wood, and stone. Fence structure and composition are selected on the basis of initial and upkeep costs, durability, strength, aesthetic characteristics, and animal safety requirements.
The fencing material that has been most widely used due to the low cost of installation and maintenance is barbed wire. However, barbed wire suffers from the disadvantage that it can cause painful and unsightly injury to valuable stock. All too frequently, animals in an agitated state are unable to detect the presence of the barbed wire, particularly in poor light conditions. Furthermore, barbed wire has a very thin cross section so that it is not easy to see; and an animal is correspondingly more apt to contact a barbed wire fence than it would be to contact a more visible barrier. In addition, barbed wire lacks the aesthetic appeal of other types of fence. Other types of wire fencing known in this art, such as web wire fencing and cyclone wire fencing, suffer from similar limitations. In addition, they tend to be expensive to install and maintain and can, over a period of time, result in the same difficulties with respect to damage to livestock as is the case with barbed wire.
In maintaining certain types of livestock, such as thoroughbred race horses, or animals of similar value, entirely wooden fences have been employed which, while pleasing to the eye and relatively safe to the animal, are expensive to install and maintain.
In an effort to obtain both the visibility of wood fencing and the low cost and maintenance of wire fencing, some fences have been constructed of wire webbing with wooden boards enmeshed therein. The durability of these fences is limited by the tendency of wood to weather and rot. Another disadvantage is the relative costliness of wood as a fencing material and the constant expense of maintaining wood fences.
In confronting the foregoing difficulties, it is known in the prior art to use metals and plastic to form fencing material such as that disclosed in U.S. Pat. No. 3,887,140, granted to Topolsek on Apr. 15, 1975 which discloses a picket fence composed of metal and plastic. The fence described there, however, while apparently well suited to applications not requiring a great deal of strength, would not appear to be suitable for applications such as the confinement of livestock or the enclosure of great spans of land.